1. FIELD OF THE INVENTION
This invention relates to index tabs of the type used for the indexing of data. More particularly, the present invention relates to index tabs constructed of flexible transparent plastic material adapted for attachment to cards or sheets and which have a tab projecting outwardly from the edge of the card or sheet to form a sheath for a label which carries an index designation.
2. DESCRIPTION OF THE PRIOR ART
Index tabs of the general type set forth above are constructed with two oppositely located spaced sidewalls adapted to straddle a card or sheet to which they are to be attached and to form the sidewalls of a sheath for carrying an index label.
In general, index tabs of the type set forth above are attached to cards or sheets by the two oppositely located sidewalls being coated with a non-drying pressure sensitive adhesive which is provided with a protective covering. The user must remove the protective covering from the pressure sensitive adhesive coatings before attaching the index tab to an intended card. It is necessary for the user of the index tab to insert his finger between the two sidewals and forcibly separate them to enable the tab to be placed astraddle a card or sheet.
If the pressure sensitive adhesive coatings are utilized, the sidewalls must be forcibly separated to facilitate the removal of the protective coverings from these adhesive coatings. Care must be exercised to prevent the sidewalls from contacting each other. If the sidewalls contact each other, they may lock in an inoperative condition, requiring separation before the index tab can be placed astraddle the edge of a card or sheet.
Index tabs of the general type set forth above may advantageously be manufactured and sold in strips which are then cut into index tab units of desired lengths by the user. In this manner a plurality of tabs may be prepackaged in a container for sale to the end user.
The need to provide an index tab with a means for separation of the adhesive surfaces prior to mounting the tab on a card or sheet is described in the prior art in U.S. Pat. Nos. 2,507,659 to P. Zalkind and 2,815,595 to K. M. Davis. Applicant has found that an improved index tab assembly is obtained if the removable or guard portion is not comprised of a plurality of portions or sections folded over one another.
In particular, with reference to FIG. 1 of Zalkind, there is disclosed a protective sheet which is joined at a portion exteriorly of the tab itself. Furthermore, the protective sheet is comprised of four overlapping layers, and still does not provide the convenience of the present invention.
The Davis patent teaches a similar construction to that described in Zalkind in that, as clearly illustrated in FIG. 3 of Davis, a plurality of overlapping segments are utilized with respect to the removable portion of the index tab. This prior art construction in addition to requiring a greater amount of paper, or other material from which the disposable portion is fabricated, still gives rise to the easy possibility of occurrence of the adhesive adjacent surfaces becoming bonded to each other.
In Zalkind when a pulling force is applied at the free end of the reentrant flaps, it will be noted that the protective strips are last to leave the area contained between the adhesive elements. Any drag or failure in continuity of movement could result in a premature closing of these leg-like elements, with the result that the adhesive surfaces become prematurely bonded to each other.
As will hereinafter be described, the present invention obviates and overcomes these deficiencies of the prior art in a new and novel manner so as to provide a superior and improved index tab.